I purchased an Xtreme HID headlights conversion kit to install in my 2004 JGC. However, someone who does automotive electrical said the light housings were not made for the heat that these bulbs will admit and the electrical system will not be robust enough to keep these preforming over the long haul. He basically said within six months or long drive with lights on they will fail.

Any truth to this and installation tricks to avoid it or was he confusing these with LED lights?

as far as electrical I ALWAYS INSIST on using a relay kit to handle the wiring. this way the power is OUTSIDE of any internal wiring and should be safe. thay alsi have a fuse for some further protection.
its might be overkill as the HID ballast is 35w same as your halogen bulb but a ballast does put out a high voltage so its best to seperate them.

It's not a good idea to run HIDs in stock housings, most of us that have them run them in housings with projector lenses. We also run them with ballasts. The only thing you'll need is the housings and ballasts and you'll be fine. Check out carid.com, they have some on there you can take a look at.